Automatic circuit breaker



Aug. 25,1953 A. R. NORDEN AUTOMATIC CIRCUIT BREAKER Filed Dec. 9, 1949 INVENTOR. HLBYfl VDEH 1?. NORDEN BY 176. a;

diam/ ($1644.)

14 7 7' OfP/VEKST Patented Aug. 25, 1953 AUTOMATIC CIRCUIT BREAKER Alexander R. Norden, Maywood, N. 1., allignor to Federal Electric Products Company, Newark,

N. 1., a corporation Application December a. 1940, Serial No. 132,110

(01. zoo-11s) 18 Claims.

This invention relates to operating mechanisms for automatic circuit breakers, and more particularly, to a novel spring link construction cooperatively associated with the actuating means of such circuit breakers.

One object of this invention is the provision of a normally resilient link connected between a pivoted handle and a pivoted actuator and latch member and constructed so that it becomes substantially non-resilient or rigid when the handle is moved toward open circuit position, thereby positively moving the actuator to relatching position, and so that it regains its normal resiliency when the breaker is in closed circuit position thereby assuring proper pressure between the contacts as the latter wear.

Another object is the provision of a simple, inexpensive and eflicient spring link which is well adapted to be used in an operating mechanism of an automatic circuit breaker of the general type shown in U. S. Patent No. 2,209,319.

Other features, objects and advantages of the present invention will become apparent from the following description considered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. l is a side elevation view of a circuit breaker embodying the present invention;

Fig. 2 is a front view thereof;

Fig. 3 is a side elevation view with the cover removed, the circuit breaker mechanism being in its closed-circuit position;

Fig. 4 is a view similar to Fig. 3 but showing the circuit breaker mechanism being in its open-circuit position;

Fig. 4A is a fragmentary view similar to Fig. 3.

showing the operating parts in a different position;

Fig. 5 is a sectional view on the line 5-5 of F1 1;

ig. 6 is a perspective view of a spring link forming a part of the circuit breaker mechanism.

Referring now to the drawings, the present invention may be used with a circuit breaker indicated generally by the numeral I0. As illus-- trated in Fig. 2 the circuit breaker comprises a two-part insulated housing or casing. One part I2 is formed with a recess containing the circuit breaker mechanism, while the other part 14 constitutes a cover. Each of said parts is formed of insulation preferably by a molding operation. The two parts of the housing or casing interfit and are secured together in housing defining relation in any suitable way, for example by bolts l6. Casing part l2 has an open recessed portion I! which forms an arcing chamber so that arc-formed gases may escape to the exterior of the housing through vent 2|. The top of casing part I2 is provided with a recessed portion which defines an opening 22 through which handle 24 projects for manual operation of the circuit breaker mechanism. Stops 23 and 25, respectively, of casing part l2 limit the pivotal movement of said handle 24. Te minal member 34 and stationary contact 36 secured thereto are positioned in open recess portion of casing part I! while terminal member 38 is fixed in open recess portion 32. One end of flexible conductor 39 is secured to terminal member 38, while the other end is secured to thermal member 48.

, Referring now to the circuit breaker mechanism in particular, the handle 24 is preferably formed with a pair of aligned opposed pivot pins 26 projecting from both sides of the handle, said pins being received in aligned bearing recesses 28 formed in the companion casing parts I 2 and i 4, respectively, for pivotal movement therein. A movable contact member-40 is mounted by pivot pin 42 in casing parts i2 and I4 for pivotal movement, the opposite ends of pivot pin 42 being received in aligned bearing recesses 44 in said casing parts I 2 and M, respectively.

Saidmovable contac member 40 is provided at one end thereof with a contact 46 which is engageable with and disengageable from stationary contact 36. Said movable contact member moves in recessed guide slot 4| defined by guide member 43 which is formed integral with the casing part i2. End portion 82 of movable contact 46 abuts step 84 of casing part I2 in disengaged condition of the companion contacts, said step serving to limit the movement of the movable contact member in its circuit opening position. A thermal, current-responsive member 48 which is preferably a thermostatic, bi-metaliic flexible strip is riveted or otherwise secured at one end thereof to a side edge of movable contact member 40. The free end .of the bimetallic strip is positioned to releasably engage a latch element 53 at one end of one arm of an actuator or lever 50 pivotall mounted at 5| on the end of the movable contact member opposite to the end that carries contact 46, said actuator 50 being insulated from said movable contact member. The actuator 50 is more specifically described in the co-pending application of Thomas M. Cole, Serial No. 127,433, filed November 15, 1949, which is owned by the assignee of aeeaa'sr my present application. Said member 58 is generally channel-shaped so as to straddle the adjacent end of member 48, said actuator 58 having laterally spaced opposing walls 86, 88 and an integral connecting portion 88 which is provided with the aforementioned latch element, depending below said opposing walls (Fig. 5). The circuit breaker mechanism, as so far described, is of the general type shown in the above mentioned patent, in Patent No. 2,459,427 and in said application of Thomas M. Cole.

In accordance with the present invention, a link 52 of special construction operatively connects handle 24 to actuator 50. More particularly, said link 52, which is non-extensible, yet resiliently contractable, connects the companion handle 24 to the adjacent arm of actuator 50.

Link 52 is formed in one piece of spring wire, and comprises a partially convolute portion 12 at one end of which is a co-planar, linear extension 14. Linear portion 16 extends from said linear extension 14 and is co-planar with and substantially perpendicular thereto. Said link operatively connects the handle and the actuator by means of a pair of arms or pivot portions 18 and 80 of which arm 18 extends transversely from the other end of convolute portion 12 and passes with slight clearance through a pair of aligned openings 54 in the actuator 50, while the other arm 80 extends transversely from linear portion I6 and passes with slight clearance through an opening 56 in handle 24. In the operation of the circuit breaker, when thermal member 48 deflects due to an excess overload of current, latch element 53 of actuator 55 is released from said thermal member causing the contacts to open as shown in Fig. 4. The link 52 becomes rigid due to side edge 60 of the. link bearing against the adjacent side edge 58 of the link, when the handle 24 is moved clockwise, viewing Figs. 3 and 4A, forming a positive connection between the actuator and the handle. In this open-circuit position, in the event that the latch element 53 of the actuator 58 is caught or jammed or resisted excessively by the top face 49 of the thermal strip as illustrated by Fig. 4A, the movement of handle 24 toward stop 25 results in the link 52 becoming rigid while the handle is thus moved so that the resistance of strip 49 to the movement of member 58 to latching position (Fig. 4) is overcome. As shown in Fig. 3, with the handle in closed circuit position, side edge 58 of link 52 becomes separated from side edge 60 causing the link to resume its normal resiliency thus permitting proper pressure between the contacts as they wear. The operating member or handle 24 cooperates with the link 52 to form a normally locked or overset toggle, and the force resiliently applied by the link 52 serves not only to maintain the proper contact pressure but also to hold the toggle in the overset position as shown.

A compression coil spring 62 placed between the movable contact member 40 and companion handle 24 operates to bias the movable contact member and the handle to its open circuit position. One end of the coil spring engages a lug 64 on handle 24, and the other end of said spring engages a lug 66 integral with the companion movable contact member 40.

The thermal current responsive member 48 may be operable not only in response to the heating effect of the current passing through it, but there is preferably additional means for operating said member independently of the response d of said strip itself to the current, said means being similar to and operating in substantially the same way as the electro-magnetic means in said Humpage Patent No. 2,459,427. Said additional means comprises an electromagnetic member 88 mounted on thermal member 48 near the free end thereof and which has a companion rigid armature 10 secured on movable contact member 40 by riveting or otherwise, and is dis- Posed in spaced confronting relation to the electromagnetic member. It will be understood that when excess current flows through thermal current-responsive member 48, the magnetic attraction between members 68 and 18 results in the deflection of thermal strip 48 for disengaging the latter from the companion latch element of the actuator 50, and in this connection it will be understood that since member I5 is rigid and thermal member 48 which carries electromagnetic member 68 is flexible, member 68 is movable by magnetic attraction toward member 10, thus deflecting or unlatching thermal member 48 from the latch element 53 of the actuator 50.

Certain of the features illustrated and de-- scribed herein are claimed in the previously identified and prior filed application of Thomas M. Cole, assigned to the assignee hereof.

It'is to be understood that what I have shown and described is a presently preferred embodiment of my invention, but it will be apparent to those skilled in the art that various changes in the details of construction and arrangement of the parts may be made without departing from the underlying idea or principles of the invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a normally resilient link connected between said handle and said latch member, said link being resiliently stressed by said handle when the latter is moved to closed-circuit position so as to resiliently hold said contacts in engagement with each other in the closed condition of the circuit breaker, and having opposing parts disposed to releasably engage each other when the handle is moved toward circuit-open position so as to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position.

2. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a normally resilient link having end portions connected to said handle and latch member, respectively, and an intermediate flexible portion whereby to resiliently hold said contacts in engagement with each other in the circuit-closed position of said handle, said flexible portion havacsaaai ing opposing parts disposed to releasably engage each other when the handle is moved toward circuit-open position so as to provide a; positive connection between said handle and said latch member for positively moving the latter by the movement oi! said handle toward circuit-open position.

3. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch memher and a flexible control member releasably engaged by said latch member for moving one 0! said contacts into engagement with the other or said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a normally resilient link connected between said handle and said latch member, said link being resiliently stressed by said handle when the latter is moved to closed-circuit position so as to resiliently hold said contacts in engagement with each other in the closed condition of the circuit breaker, and having opposing parts disposed to engage each other to furnish a substantially nonresilient action on said latch member when the handle is moved toward circuit-open position so as to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position, said flexible control member being a flexible strip which releases said latch member upon overload, and spring means for moving said handle to its circuit-open position when said latch member is released by said strip, said movement of the handle to opencircuit position under the force of said spring bein transmitted through said engaged opposing parts to cause movement of said latch member to a position thereof to relatch with said strip upon the return of the latter to its normal condition.

4. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circult-open and circuit-closed positions; a normally resilient link having end portions connected to said handle and latch member, respectively, and an intermediate flexible portion whereby to resiliently hold said contacts in engagement with each other in the circuit-closed position of said handle, said flexible portion having opposing parts disposed to releasably engage each other when the handle is moved toward circuit-open position so as to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position, said latch member being pivotally connected to one of said contact members and having spaced sides at opposite sides of the latter and provided with aligned apertures adjacent one end of said latch member and one of said end portions of said link pivotally engaging said latch member in said apertures.

5. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle !or manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a normally resilient link connected between said handle and said latch member, said link being resiliently stressed by said handle when the latter is moved to closed-circuit position so as to resiliently hold said contacts in engagement with each other in the closed condition of the circuit breaker, and having opposing parts disposed to releasably engage each other when the handle is moved toward circuit-open position so as to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position, said latch member being pivotally connected to one of said contact members and having spaced sides at opposite sides of the latter and provided with aligned apertures adjacent one end of said latch member and said link having an end portion engaging said latch member in said apertures.

6. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuitopen and circuit-closed positions; a normally resilient link connected between said handle and said latch member, said link being resiliently stressed by said handle when the latter is moved to closed-circuit position so as to resiliently hold said contacts in engagement with each other in the closed condition of the circuit breaker, and having opposing parts disposed to releasably engage each other when the handle is moved toward circuit-open position so as to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuitopen position, said latch member being pivotally connected to one of said contact members and having spaced sides at opposite sides of the latter and provided with aligned apertures adjacent one end of said latch member and one of said end portions of said link pivotally engaging sa latch member in said apertures.

'7. In an automatic circuit breaker having relatively movable contact members provided with companion contacts respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a normally resilient link connected between said handle and said latch member, said link being resiliently stressed by said handle when the latter is moved to closed-circuit position so as to resiliently hold said contacts in engagement with ea'h other in the closed condition of the circuit breaker, and having opposing parts disposed to engage each other to furnish a substantially nonresilient action on said latch member when the handle is moved toward circuitopen position so as to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position, said latch member being pivotally connected to one of said contact members and having spaced sides at opposite answer sides of the latter and provided with aligned apertures adjacent one end of said latch member and said link having an end portion engaging said latch member in said apertures, said flexible control member being a flexible strip which releases said latch member upon overload, and spring means for moving said handle to its circuit-open position when said latch member is released by said strip, said movement of the handle to open-circuit position under the force of said spring being transmitted through said engaged opposing parts to cause movement of said latch member to a position thereof to relatch with said strip upon the return of the latter to its normal condition.

8. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a normally resilient link having end portions connected to said handle and latch member, respectively, and an intermediate flexible portion whereby to resiliently hold said contacts in engagement with each other in the circuit-closed position of said handle, said flexible portion having opposing parts disposed to releasably engage each other when the handle is moved toward circuit-open position so as to provide a positive connection between said handle and said latch membeer for positively moving the latter by the movement of said handle toward circuit-open position, said flexible control member being a flexible strip which releases said latch member upon overload, and spring means for moving said handle to its circuit-open position when said latch memberis released by said strip, said movement of the handle to open-circuit position under the force of said spring being transmitted through said engaged opposing parts to cause movement of said latch member to a position thereof to relatch with said strip upon the return of the latter to its normal condition.

9. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operatin said latch member and movable to and from circuit-open and circuit-closed positions; a normally resilient link connected between said handle and said latch member, said link being resiliently stressed by said handle when the latter is moved to closed-circuit position so as to resiliently hold said contact in engagement with each other in the closed condition of the circuit breaker, and having opposing parts disposed to releasably engage each other when the handle is moved toward circuit-open position so as to provide a positive connection between said handle and said latch member for positively moving the latter by th movement of said handle toward circuit-open position, said flexible control member being a flexible strip which releases said latch member upon overload, and spring means for moving said handle to its circuit-open position when said latch member is released b said strip, said movement of the handle to openclrcuit position under the force of said spring being transmitted through said engaged opposing parts to cause movement of said latch member to a position thereof to relatch with said strip upon the return of the latter to its normal condition.

10. In an automatic circuit breaker having relatively movable contact members provided with companion contacts,'respectively, a latch member'and a flexible control member releasably engaged by said latch member for movin one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a normally resiliently link having end portions connected to said handle and latch member, respectively, and an intermediate flexible portion whereby to resiliently hold said contacts in engagement with each other in th circuit-closed position of said handle, said flexible portion having opposing parts disposed to releasably engage each other when the handle is moved toward circult-open position so as to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position, said latch member being pivotally connected to one of said contact members and having spaced sides at opposite sides of the latter and provided with aligned apertures adjacent one end of said latch member and one of said end portions of said link pivotally engaging said latch member in said apertures, said flexible control member being a flexible strip which releases said latch member upon overload, and spring means for moving said handle to its circuit-open position when said latch member is released by said strip, said movement of the handle to open-circuit position under the force of said spring being transmitted through said engaged opposing parts to cause movement of said latch member to a position thereof to relatch with said strip upon the return of the latter to its normal condition.

11. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a link comprising 'a unitary metallic member having two parallel pivot portions engaged in said latch member and said handle, respectively, and a connecting portion between said pivot portions, said connecting portion having opposing parts disposed to releasably engage each other when the handle is moved toward circuitopen position to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position, said parts being mutually spaced in the circuit-closed position of said handle whereby to resiliently hold said contacts in engagement with each other in the closed condition of the circuit breaker.

1 In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a link comprising a unitary metallic member having two parallel pivot portions engaged in said latch member and said handle, respectively, and a connecting portion between said pivot portions, said connecting portion having opposing parts disposed in intersecting planes for the releasable engagement thereof when the handle is moved toward circuit-open position so as to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position. 4

13. In an automatic circuit breaker having relatively movable contact members provided with companion contacts, respectively, a latch member and a flexible control member releasably engaged by said latch member for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said latch member and movable to and from circuit-open and circuit-closed positions; a link comprising a unitary metallic member having two parallel pivot portions engaged in said latch member and said handle, respectively, and a convolute connecting part, said part having at one end thereof a coplanar angular extension connected to one of said pivot portions, and at its other end said part being connected directly to the other of said pivot portions whereby said link is provided with opposing side edges disposed to releasably engage each other when the handle is moved toward circuit-open position to provide a positive connection between said handle and said latch member for positively moving the latter by the movement of said handle toward circuit-open position, said side edge being mutually spaced in the circuit-closed position of said handle whereby to resiliently hold said contacts in enagement with each other in the closed condition of the circuit breaker.

14. In a circuit breaker mechanism comprising a movablecontact member, actuating means,

a handle for manually operating said actuating means, and a thermal current responsive member carried by and movable with said contact member and operable to latch said actuating means to the contact member and to unlatch the same in response to predetermined current in the circuit, a normally resilient link interconnected between said handle and said actuat ing means, said link being resiliently stressed by said handle when the latter is moved to closed circuit position so as to resiliently hold said contact member in the closed circuit position thereof, and having cooperating portion; disposed to provide a substantially non-resilient action on said actuating means when the handle is moved to circuit-open position so as to provide a. positive connection between said handle and said actuating means for positively moving the latter by movement of said handle toward circuit-open position.

15. In a circuit breaker having relatively movable companion contacts, actuating means, a flexible control member releasably engaged by said actuating means for moving one of said contacts into engagement with the other of said contacts, and a handle for manually operating said actuating means and movable to and from circuitopen and circuit closed positions, a normally resilient link connected between said handle and said actuating means, said link being resiliently stressed by said handle when the latter is moved to closed circuit position so as to resiliently hold said contacts in engagement with each other in the closed condition of the circuit breaker, and

said link having cooperating means to provide a positive connection between said actuating means and the handle when the latter is moved to circuit-open position for positively moving said actuating means by the movement of said handle toward circuit-open position.

16. A circuit breaker, as defined in claim 15, further characterized in that said cooperating means are constituted by cooperating integral portions of said link.

17. A link for a circuit breaker comprising a unitary member formed of spring metal and having a pivot portion at each end thereof and a connecting portion between said pivot portions, said connecting portion having cooperating parts normally spaced from each other in the circuit closed condition of the circuit breaker for providing a resilient connection in said circuit closed condition, said parts being adapted to mutually engage upon opening of the circuit breaker for providing a positive connection in said circuitopen condition.

18. A link, as defined in claim 17, further characterized in that said parts are in opposing disposition in said link.

. ALEXANDER R. NORDEN.

References Cited in the file of this patent 

